Note: Descriptions are shown in the official language in which they were submitted.
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FIELD OF THE INVENTION
The present invention relates generally to semi-
s finished wood simulating products an3 methc.ds, and more
particularly to semi-finished products capable of
accepting wood stain, paint or varnish as applied by an
end user at an installation site and methods of
manufacturing semi-finished wood simulating products.
BACKGROUND OF THE INVENTION
There is a need to substitute wood simulating
products for solid or real wood products to reduce
material costs. This need to substitute simulated wood
products for real wood is particularly acute for hardwood
products. These hardwoods include woods such as lauan
mahogany, and other woods of that same family, the bulk
of which come from the Philippines and other pacific and
forest locations. Over the last ten years, the
availability of such woods has greatly diminished, and
the remaining supply has diminished markedly in quality.
There are also substantial environmental issues and
concerns affecting both the quality and quantity of the
real wood supply, in part, because these woods come from
"rain forest" areas which have been "harvested" over the
years as part of a general land clearing program which
did not include replanting, etc.
A traditional method of manufacturing simulated wood
products such as paneling, or door-skins for hollow core
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doors, involves utilizing a non-solid wood substrate such
as a wood composite or fiberboard substrate and
overlaying this substrate with a paper overlay and then
applying a protective coating to the paper overlay.
Vinyl overlays may also be used. There are numerous
problems inherent in the traditional methods. These
problems include the risk of the paper or vinyl overlay
product peeling from the substrate. Another problem is
that bubbles and blisters sometimes occur in the overlay
l0 process. Other problems are that the protective coating
is not cleanable with a solvent or capable of being
sanded to eliminate surface imperfections and scratches
which occur during shipping and handling. Most
importantly, the type of wood being simulated and the
color of its stain must be determined at the
manufacturing facility and is not changeable by the user
at the installation site.
OBJECTS AND SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention
to provide a product and method for manufacturing semi-
finished wood simulating products which eliminate or
obviate the above mentioned problems.
It is another object of the present invention to
provide a product capable of accepting stain, paint, or
varnish as applied by an end user at the installation
site.
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It is another object of the present invention to
provide a pro:uct that simulates the visual appearance
and tactile qualities of real wood.
It is another object of the present invention to
provide a pro3uct that is more durable than existing
products and can be lightly sanded to eliminate scratches
and surface imperfections.
It is another object of the invention to provide a
product that can be cleaned with a solvent.
It is yet another object of the present invention to
provide a semi-finished wood simulating product which is
simple in construction, effective in use and economical
to manufacture.
These objects are achieved by providing a substrate
having at least one surface to be finished. A liquid
basecoat is applied on the substrate and dried. A wood
grain pattern is deposited, in liquid form, on the
basecoat. Some of the pattern is transferred from the
originally deposited position on the basecoat to~a
subsequent position. The pattern is then cured. A
polymerizable protective coating is applied onto the
substrate overlying the basecoat and the pattern. The
protective coating seals the substrate and is adapted for
accepting a colorant to be applied by an end user. The
protective coating is then polymerized. Additionally, if
a porous substrate is provided, a sealer is applied prior
to the liquid basecoat and is then cured.
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These and other objects of the present invention
will become apparent from the following detailed
description and appended claims.
The invention may best be understood with reference
to the accompanying drawings wherein illustrative
embodiments are shown.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic illustration according to
the present invention depicting a conveyor line for
manufacturing a semi-finished wood simulating product;
Figure 2 is an exploded cross-sectional view showing
a porous substrate and various layers of coatings applied
to the porous substrate;
Figure 3 is an exploded cross-sectional view showing
a non-porous substrate and various layers of coatings
applied to the non-porous substrate;
Figure 4a is a side elevational view of a high
pressure roller; and
Figure 4b is a front elevational view of the high
pressure roller of Figure 4a.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to Figure 2, semi-finished wood
simulating product 100 includes a substrate 102, a sealer
108, a top or base coat 110, a printed wood grain pattern
(not shown), and a protective coating 112. Substrate 102
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may be a composite wood material, such as pressboard or
medium density fiberboard, having a porous composite
layer 104 and a backing layer 106. Sealer 108 is applied
to a porous surface 114 of substrate 102 to create a
uniformly impermeable surface on which to apply
subsequent materials. A thick, colored, viscous basecoat
110 is roller applied to sealed surface 114, with the
color selected to reflect the general "background ambient
color" of the wood being simulated. A wood grain pattern
(not shown) chosen to simulate a particular wood, is then
printed on basecoat 110. A protective coating 112 is
applied to protect the wood grain pattern. The
protective coating 112 is transparent/translucent so that
the printed wood grain pattern is visible through
protective coating 112. Protective coating 112 is
sufficiently porous so as to be stainable by the end user
at the installation site. Protective coating 112 is also
hard enough to allow the product to be stacked and
shipped horizontally, without substantial degradation
occurring to the outer surface of protective coating 112.
A second embodiment of the present invention is
shown in Figure 3. A semi-finished wood simulating
product 120 includes a non-porous substrate 122, such as
sheet metal, a thick, colored, viscous basecoat 110
applied thereon, a wood grain pattern printed (not shown)
on basecoat 110, and a protective coating 112 applied to
protect the wood grain pattern.
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Sealer 108 is used to avoid blotching when a
substrate having a rorous surface to be finished is going
to be stained by the end user at the installation site,
and is therefore not necessary with the product 120 and
its non-porous substrate 122. Stain or colorant applied
by the end user may penetrate the entire protective layer
112 and even the basecoat 110 and, but for sealer 108,
into the porous surface 114. Because the
hardness/absorbability of the underlying composite wood
materials is non-uniform (i.e., varies throughout a given
sheet), the stain would be able to penetrate the
underlying porous surface in some places and not in
others, and thus create a blotchy look. Basecoat sealer
108 is not necessary when using a non-porous substrate,
or if only varnish or paint is to be applied by the end
user.
The method of manufacturing a semi-finished wood
simulating product can best be understood with reference
to Figure 1. It should be understood that the layout
shown is for illustrative purposes only and the layout
and size of each of the elements is not meant to be
limited. For purposes of completeness, the method of
manufacturing will be described with reference to a
product utilizing a composite wood substrate 102. It
will be understood that the product could also be
manufactured using a non-porous substrate 122 by
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eliminating some of the process steps required to process
a product using a composite wood substrate.
Substrate 102 enters a horizontal conveyor system
at multi-brush cleaning station 10 with surface 114
facing upwardly. Surface 114 of substrate 102 is cleaned
using multi-rotary brushes, which clean the surface;
adhesion of the subsequent layers may be adversely
affected if surface 114 is not clean.
Conveyor portion 12 transports clean substrate 102
to direct roll coating station 14 where liquid sealer 108
is applied to surface 114. Sealer 108 is an acrylic
sealer, preferably from AKZO Coatings, Inc. under their
product number 641-Y029-42. Conveyor system C then
transports substrate 102 having sealer 108 to an infrared
oven 16, which cures and sets sealer 108.
Substrate 102 having a dry sealer 108 then enters a
first direct roll coating station 22 where liquid
basecoat 110 is applied. Basecoat 110 is a low volatile
organic content (~'VOC") water based vinyl acrylic
copolymer having a viscosity of 38 seconds on a #2 Zahn
cup, and is available from AKZO Coatings, Inc. under
their product number 651-W029-12.
A conveyor portion 20 then transports substrate 102
having wet basecoat 110 to a second direct roll coating
station 22. Due to the length of conveyor portion 20,
the first layer of basecoat begins to level on account of
the dwell time. A second layer of the basecoat is then
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applied on the first layer of basecoat, each layer having
a thickness of approximately 0.003 inches. The second
layer of basecoat is then allowed to level while being
transported on conveyor portion 24.
The controlled viscosity of basecoat 110 causes the
basecoat 110 to have the tactile qualities, when dry, of
raw wood. Because the basecoat is applied in two coats,
then the resulting thickness must be controlled. If the
basecoat is too thick, it may crack and thus be unusable
for the resulting product. Because the basecoat 110 is
applied in two coats, then if sealer 108 is not covered
by the first layer of basecoat 110 it will be covered by
the second layer of basecoat 110.
The conveyor portion 24 then transports substrate
102 having two coats of wet basecoat 110 to two
sequential dual high velocity ovens 26 and 28. Oven 26
is set to approximately 250° F., in order to prevent the
basecoat 110 from forming a skin, and oven 28 is set to
approximately 375° F. The dwell time of substrate 102 in
dual ovens 26 and 28 is approximately 15 seconds, with
the surface temperature when exiting the oven 28 being at
about 131° F. The ovens 26 and 28 are each convection
ovens, which cause the solvent to be moved relatively
rapidly away from the substrate. The ovens 26 and 28 dry
and set the two layers of the basecoat.
A conveyor portion 30 then transports substrate 102
from oven 28 to a brush station 32. The basecoat 110
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layers are allowed to cool in ambient air during the
transport because of the d~~ell time achieved. Basecoat
110 should be dry and hard so that basecoat 110 is not
malleable. At brush station 32, the outer surface of the
second layer of basecoat 710 is burnished with high speed
rotary brushes which remove grooves in the basecoat 110
and any fibers and the like lying upon the surface.
A conveyor portion 34 then transports substrate 102
to a rotogravure print station 36. While on conveyor
portion 34, the burnished surface of basecoat 110 cools
to remove the heat from the burnishing operation.
Substrate 102 is sequenced prior to entering print
station 36 in preparation for wood grain printing. A
wood grain pattern, such as of mahogany, teak, or oak, is
applied using conventional rotogravure technique at print
station 36. The wood grain pattern is printed with an
acrylic print ink available from AKZO Coatings, Inc.
under their product number 699-C029-370A.
Print station 36 includes a 48 inch print cylinder
(not shown) underneath which rolls substrate 102.
Substrate 102 has a length of about 80.5 inches, and each
substrate 102 is sequenced for entry into print station
32 so that no two print patterns are exactly the same.
The pattern is randomly printed on basecoat 110 by timing
entry of the input edge of each substrate 102 relative to
the print drum. Thus, each substrate 102 has certain
unique properties and characteristics, which, although
subtle, enhance the real wo~3 look and feel.
A conveyor portion 38 then transports the substrate
having a wood grain pattern printed thereon to a rotary
print transfer station 40. During this approximately 9
second transport, the print ink begins to dry and
portions become tacky. As best shown in Figures 4a and
4b, rotary print transfer station 40 includes a high
pressure roller assembly 42 including a roller 44 and a
screw jack pressing mechanism 46. Roller 44 is
approximately six inches in diameter, and is made of a
modified polyvinyl-type rubber having a 45 - 50
durometer. Roller 44 rolls relative to lead or input
edge of substrate 102 to the opposite or exit edge.
Screw jacks 46 press roller 44 against the drying wood
grain pattern so that the wet or tacky ink on the surface
of basecoat 110 is picked up by roller 44 and then
transferred to a circumferentially spaced location where
the wet and tacky portions are then reapplied to basecoat
110. Thus the print pattern has voids and skips which
enhance the uniqueness of the product because no two
appear exactly alike. The finish achieved resembles
distressed wood.
A conveyor portion 60 then transports substrate 102
to a direct roll coater 62. While on conveyor portion
60, the print ink of the grain pattern dries. Direct
roll coater 62 applies a first layer of a protective
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coating 112. Protective coating 112 is an acrylic/amino
low volatile organic content, high solids, pigmented
temperature converted or polymerizable coating available
from AKZO Coatings, Inc., under their product number 681-
C029-123. The viscosity of protective coating 112 is 22
seconds on a #2 Zahn cup. Protective coating 112
includes a methane sulfonic acid catalyst available from
AKZO Coatings, Inc., under their product number G49-
PJ029-23. The catalyst is 9% by volume of protective
l0 coating 112. The first layer of protective coating has a
thickness of approximately 0.003 inches.
A conveyor portion 64 then transports the substrate
102 to a second direct roll coater 66 where a second
layer of the protective coating 112 is applied. Because
protective coating 112 is applied in two coats, it is
ensured that, if the wood grain pattern is not covered by
the first layer of protective coating 112, then it will
be covered by the second layer of protective coating 112.
A conveyor portion 68 transports substrate 102
having two uniform layers of protective coating 112
applied thereon to two dual high velocity ovens 70 and
72. Substrate 102 remains on conveyor portion 68 for
approximately 3 seconds to allow protective coating 112
to level.
Dual high velocity ovens 70 and 72 set the coating
112 and remove the low volatile organic content
cosolvents therefrom. Oven 70 is set to approximately
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275° F., and oven 72 is set to approximately 300° F. The
entering temperature of substrate 102 to oven 70 is about
92° F, and the surface temperature when exiting oven 72
is about 185° F.
Conveyor C then transports substrate 102 having two
layers of protective coating 112 thereon to an infrared
oven 74. Oven 74 is set at approximately 1,700° F, so
that full polymerization of coating 112 is achieved.
Full polymerization occurs at a temperature of about 300°
F, and occurs at the surface of protective coat 112 at a
transport speed of 200 feet per minute. Satisfactory
polymerization is achieved at a surface temperature of
220° F. Polymerization of protective/stainable coating
112 occurs while substrate 102 is in oven 74.
A conveyor portion 76 then transports substrate 102
having a polymerized protective coating 112 thereon to a
combination chiller-humidifier 78. During this time,
product 100 is allowed to cool in ambient air. Chiller-
humidifier 78 rapidly reduces the temperature of product
10o to about 124° F, and rehumidifies the product prior
to stacking.
A conveyor portion 80 then transports product 100
from chiller-humidifier 78 to a stacking station 82 where
product 100 is stacked. The stacks may be lifted by a
fork lift for transfer to a flat bed or the like so that
the resulting semi-finished products 100 may be
transported to the end user.
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It should be understood that two layers of
stainable/protective coating 112 produce a coating which
is both durable and thick enough to permit the surface to
be lightly sanded so that imperfections and scratches
which may occur can be removed. The end user can finish
the outer surface of stainable/protective coating 112 to
whatever color is desired, which is something that the
user cannot do with any of the other alternatives and is
otherwise only available from real wood. Because the
coating 112 is colorable by the end user, either by
staining or painting, then the end user may select the
finished color. The end user coloring does not, however,
completely mask the wood grain pattern.
It should also be understood that the outer surface
of backing 106 is frequently textured. This means that
the textured back of the next to the bottom product being
stacked in stacking station 82 presses against the outer
surface of the bottom product with a force of as much as
4,000 lbs. throughout the shipping process. The
disclosed coating formulation and application~process
creates a surface which is hard enough to withstand the
shipping process, and yet porous enough to be readily
stained and finished on site.
It should be noted that the process results in a
product which has the look and feel of an unfinished
piece of wood, which may then be used to manufacture a
hollow core door or the like which is then sold
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unfinished to the user. This allows the end user to
either paint the doors as he might any other wood door,
or in the alternative to varnish the door, or to stain
the doors and then apply protective varnish coat over the
stain surface. Alternatively, the semi-finished product
of the invention may be used to create paneling, veneers,
and like wood-appearing surfaces.
While this invention has been described as having a
preferred design, it is understood that it is capable of
further modifications, uses, and/or adaptations thereof
following in general the principles of the invention and
including such departures that have been known or
customary practice in the art to which the invention
pertains.
